When choosing a laptop, it’s important to find out if you will need to run any course-specific software, and then buy something that runs it. After that, the big decision is whether you want something that you can carry around all day and, nowadays, whether you would benefit from a hybrid Windows PC that also works as a tablet.
You appear to have made those decisions so the question is relatively simple.
If you want an android based tablet, you can have a look on Chromebook, which is 2 in 1 and cheap enough.
There are dozens of Windows laptops with 15.6in screens at prices from about £250 to £400, and these make up the bulk of the mass market. The competition is fierce and driven by price rather than the quality of the screen and keyboard, or even the speed, and this encourages manufacturers to cut corners.
Under the circumstances, it’s a good idea to get hands-on experience of a laptop, to see if the screen is bright and sharp, and to check whether it feels solid enough.